Load cells are being used more frequently because of the high accuracy one is able to obtain with such a device. In a load cell, strain gages are used to determine a load by measuring compression created in a portion of the strain gages and tension created in the balance of the strain gages as a result of the load being applied to the load cell. In single point load cell scales, the strain gages are located on opposite sides of the transfer point with those on one side being under compression and those on the other side being under tension when a load is applied. In prior load cells relatively large units were assembled and a load was transferred through a ball bearing under compression as disclosed in U.S. Pat. Nos. 4,037,675 and 4,170,270.
Recently, load cell scales of a unitary, or monolithic, construction have been proposed wherein the entire assembly is made of one piece. Such a load cell is shown and described in U.S. Pat. No. 4,181,011. The connector between the load beam and sensing beam is integral with these two beams and is machined in order to achieve the proper configuration. With this construction, the load beam is located below the sensing beam and when a load is to be determined, the load is transferred through the connector under tension. The advantage of such a structure is that one need not be concerned with connector buckling problems. The connecting member between the load beam and sensing beam is generally relatively long and narrow because it must flex. This can raise problems relative to buckling of the connector if the load is transferred in such a way as to place the connector under compression. The shortcoming of such prior structures is that they are expensive to produce, requiring accurate, time-consuming machining. In addition, the connectors of prior art devices of unitary construction, whose connectors are under tension when a load is placed thereon, have certain structural strength problems. As is well known, materials have less tensile strength than compressive strength so that in cases of overload or shock the connector in the prior structure could rupture.